package com.atguigu.common.jwt;

import io.jsonwebtoken.*;
import org.springframework.util.StringUtils;

import java.util.Date;

public class JwtHelper {
    private static long tokenExpiration = 365 * 24 * 60 * 60 * 1000;
    private static String tokenSignKey = "123456";

    public static String createToken(Long userId,String username){
        return Jwts.builder()
                .setSubject("AUTH-USER")
                .setExpiration(new Date(System.currentTimeMillis() + tokenExpiration))
                .claim("userId",userId)
                .claim("username",username)
                .signWith(SignatureAlgorithm.HS512,tokenSignKey)
                .compressWith(CompressionCodecs.GZIP)
                .compact();
    }

    public static Long getUserId(String token){
        try{
            if(StringUtils.isEmpty(token))  return null;
            Jws<Claims> claimsJws = Jwts.parser().setSigningKey(tokenSignKey)
                    .parseClaimsJws(token);
            Claims claims = claimsJws.getBody();
            Integer userId = (Integer)claims.get("userId");
            return userId.longValue();
        }catch(Exception e){
            e.printStackTrace();
            return null;
        }
    }

    public static String getUsername(String token){
        try{
            if(StringUtils.isEmpty(token))  return "";
            Jws<Claims> claimsJws = Jwts.parser().setSigningKey(tokenSignKey)
                    .parseClaimsJws(token);
            Claims claims = claimsJws.getBody();
            return (String)claims.get("username");
        }catch(Exception e){
            e.printStackTrace();
            return null;
        }
    }

    public static void main(String[] args) {
        String token = JwtHelper.createToken(4L, "li4");
        System.out.println(token);
        System.out.println(JwtHelper.getUserId(token));
        System.out.println(JwtHelper.getUsername(token));
    }
}
